butler



' 3 Sheets-Sheet 1, M.BUTLER. DENTAL CHAIR.

(No Model.)

Patented Jan. 31, 1893.

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(No Model.) 3 Sheets-Sheet 2 M. BUTLER.

DENTAL CHAIR.

No. 490,637. Patented Jan. 31, 1893.

MEJML (No Model.) 3 SheefiF-Sheet a.

M. BUTLER.

DENTAL GHAIR.

No. 490,637. Patented Jam 31, 1893.

STATES ATZENT FFIoE.

MAGULER BUTLER, OF ROCHESTER, NEW YORK, ASSIGNOR OF ONE-HAIJF TO THEARCHER MANUFACTURING COMPANY, OF SAME PLACE.

DENTAL CHAIR.

SPECIFICATION forming part of Letters Patent No. 490,637, dated January31, 1893.

Application filed February 15. 1892. Serial No. 421.587. (No model.)

.To all whom it may concern:

' Be it known that I, ll/IAGULER BUTLER, of Rochester, in the county ofMonroe and State of New York, have invented certain new and usefulImprovements in Dental Chairs; and I do hereby declare the following tobe a full, clear, and exact description of the same, reference being badto the accompanying drawings, forming a part of this specification, andto the reference-numerals marked thereon.

My present invention relates to dental and similar chairs and it has forits object to provide a chair that may be raised and lowered noiselesslyand with facility and one in which the various adjustments necessary toput the patient in the most convenient position can be easily andquickly accomplished, and to these ends it consists in certain noveltiesin construction and combinations of parts, all as will be hereinafterfully described and the novel features pointed out in the claims at theend of this specification.

In the accompanying drawings: Figure l is a side elevation of a chairconstructed in accordance with my invention showing in dotted lines someof the adjustments of which-it is capable. Fig. 2 a rear elevation ofthe same. Fig. 3 a vertical section of the supportingbase and standardtaken on the line mx of Fig. 2. Fig. 4 a similar view taken on the lineyy of Fig. 1. Fig. 5 a horizontal sectional view on the line ze' of Fig.3. Fig.6 a horizontal sectional View on the line (1-?) of Fig. 3. Fig. 7a detail view of the winding drum and clutch. Fig. 8 a detail plan viewof the device for disengaging the operating treadle. Fig. 9 a section onthe line mn of Fig. 8. Fig. 10 aplan view of the seat frame. Fig. 11 asectional view of the same on the line bc. Fig. 12 a rear view of aportion of the foot rest or platform. Fig. 13 a side elevation of theplatform adjusting mechanism partly insection. Fig. 14 a sectional Viewof the back clamp taken on the line ef of Fig. 2.

Similar reference numerals in the several figures indicate similarparts.

The base or support for the chair, in which the seat supporting standardmoves, is constructed, as shown in Figs. 1 to 4, of two parts, the lowerpartembodying a ring casting or base plate 1 adapted to rest upon and,if desired,'be secured to the floor, and to the inner edges of this isbolted or otherwise secured a plate 2 upon which the upper part of thebase rests, said two parts being made integral however, if preferred.The upper part is composed of a column or casting 3 to the lower part ofwhich is attached a dish-shaped casting 4, bymeans of securing screws 5passing through the part 3 and the upturned edges of the casting. Alsosecured to this casting4 is a plate 6.

The casting 4 is provided with a depending flange 7 resting upon theplate 2 and forming a small surface upon which the part 3 or column ofthe base may be rotated, it being centered and afforded a slight bearingat the center by means of a screw 8 passing up from the bottom andpreventing its removal from the plate 2. v

Mounted upon the cover plate 6 are suitable standards 9 in which arejournaled the ends of a shaft 10 extending transversely of the base andhaving near one end and rigidly secured to it, a drum 11 preferablygrooved spirally to receive a lifting rope or cable 12 to one end ofwhich it is secured. At the other end of said shaft and rigidly securedto it is a ratchet wheel 16 and connected to this a disk 14 and sleevedupon the shaft, or an extension of the disk 14, is aloose arm 15 havinga portion projecting over the periphery of the disk 14, between whichand the disk operates a small roller 16, the edge of the projection overthe disk being inclined so that when the arm 15 is raised by means of apit- 7 man 17 .attached to the foot lever 18, the roller will bite onthe periphery of the disk and turn the latter and shaft in the directionindicated by the arrow Fig. 3. The clutch is retracted after beingoperated by the footlever by means of a spring l7 connected to thepitman and base. The connection between the clutch and the foot lever18, (which latter I is pivoted upon a pin 36 mounted in ears in the baseand extending outward in convenient position to be operated upon,) ispreferably detachable so that after the chair has been raised to theheight desired, the operator may disconnect the foot lever 18 and allowit to move down out of the way, as shown in dotted lines Fig. 3.

One form of connection which I have employed with success, and prefer onaccount of its simplicity, is shown in detail in Figs. 8 and 0 and in,this arrangement I pivot loosely upon the end of the lever, a stud 19havinga transverse aperture through which passes the pitman 17 connectedto the clutch, and I provide in the stud and extending at right anglesto said aperture, a sliding pin 20 having a recess 21 in its side, asshown in dotted lines Fig. 8, and to its outer end is secured a washer22 between which and the stud is arranged a spring 23, adapted to movethe pin in a direction to cause the solid portion to engage a suitablenotch 24 provided in the side of the pitman 17. Connected to the otherend of said pin is a link 25 pivoted to a small foot lever 26 journaledon the pivot pin 36 of the foot lever 18; the construction being suchthat under ordinary circumstances the pin 20 is projected by its springso that it will be in engagement with the notch 24 in the pitman and themovements of the lever will be communicated to the latter, but when itis desired to disconnect the lever, it is only necessary for theoperator to press with his foot on the end of the lever 26 drawing thepin 20 outward until the recess 21 is in line with the pitman, when thelatter and its clutch will be drawn to lowest position by the spring l7and the lever will also drop to the position in dotted lines Fig. 3, thepin 20 being held retracted against the tension of its spring 23 as thenotch 21. is in engagement with the solid part of the pitman. \Vhenitisdesired to use the foot lever again, it is only necessary to raiseit until the pin 20 is in line with the notch 24 when the spring willcause its reengagement and the lever may then be operated in the usualway to raise the standard.

The standard 30 slides within the column 3 of the base, having a longhearing at its upper end and its lower end is provided with a slot 31for the accommodation of the shaft 10 when the standard is lowered, andconnected to the lower part of said standard by means of a screw 32 isone end of the cable 12, which extends over the pulley 13 jonrnaled inthe upper portion of the base and down again to the drum 11 to which itis secured.

It will be seen that in order to raise the chair it is only necessary tooperate the foot lever in the usual manner (the spring 17 returning itto highest position) when the disk 14 and shaft 10 will be rotated inthe direction of the arrow Fig. 3, winding the cable 12 on the drum, thestandard then being held by means of a spring pawl 33 secured to a shaft34 extending to the exterior of the standard of the column and providedwith a foot lever 35, said pawl arresting the backward rotation of theshaft 10 and the consequent unwinding of the cable from the drum.

It is necessary to supply some means for governing the backward movementof the winding drum in order to provide for an easy and smooth descentof the standard carrying the chair seat and to provide for this, Ijournal loosely upon the shaft 10 a wheel '40 provided with a rimoverhanging the enlarged end of the drum 11 and arrange between saiddrum and wheel a clutch device, whereby the drum may be rotated freelyin a direction to wind up the cable and elevate the seat standard butwhen rotated in an opposite direction will cause the engagement of thedrum and wheel, so that the latter will move with it. This clutch maybeof any suitable construction but I prefer to employasmall roller 41arranged in a tapering recess 42 in the drum and pressed outward by aspring 43 acting upon a suitable pin or follower.

Upon the outer side of the wheel are gear teeth meshing with a smallbeveled pinion 45 secured to the upper end of a short shaft 46 journaledin the plate 6 and upon the lower end of this shaft is secured a pinion47 meshing with a gear 48 secured to a spider 49 journaled loosely upona boss or extension 58 of the casting 4, as shown in Figs. 3 and 4, andadapted to rotate loosely thereon. At the outer ends of the spider arepivoted weighted levers 50, and brake shoes 51. are arranged near thepivotal points of these levers and adapted to be pressed by them intoengagement with the vertical rim of the casting 4, as in Fig. 5.

The operation of this governing device will now be apparent. Vhen theshaft 10 is rotated in a direction to lower the chair seat by the weightof the parts and the occupant, the clutch between the drum and wheel 40will be automatically engaged and said wheel will be rotated, actuatingthe spider 49 through the gears as described, and causing the weightedarms 50 to fly outward by centrifugal force, pressing the shoes 51 intoengagement with the ring of part 4, this friction being suflicient toregulate and govern the descent, which can be arrested at any time bythe operator allowing the pawl or detent 33 to engage the ratchet wheel16.

Secured to the upper end of the seat standard 30 is a head or casting 52having laterallyprojectingarmsupon whichthe seatframe 53 is pivoted inthe usual manner, said casting being also provided with a forwardextension in which operates a bolt 54 normally pressed outward by aspring 55 to engage one of a series of recesses in a depending arm 56secured to the seat frame, by which means the seat frame is retained inposition when adjusted on its pivots, and as a means for readilyoperating said bolt I provide a lever 57 pivoted on the casting andextending outward at one side of the chair as shown in Figs. 9 and 11,and connected to the bolt by a link 59.

Depending from the forward portion of the seat frame are the slottedarms or plates 60- suitably grooved or recessed on their inner sideforming ways in which slide the platform IIO or foot rest 6l ofthechai-r, the platform having-suitable lugs or projections, forpreventing tilting, fitting the ways.

The lower ends of the arms are connected by a bolt or rod 6l 'andsurrounding this is a sleeve 62 having a bearing on the rod, to theforward portion of which are attached two arms 63 provided with rollers64 on their ends in engagement with the under side of the platform andserving to support it. Near one end of the sleeve 62 is secured a footlever 65 extending rearward and out at one side of the depending arm 60where it projects slightly over the rack segment 66 secured to or formedupon the arm 60. Pivoted upon the lever is a pawl 67, the free end ofwhich is held in engagement with the ratchet teeth by a spring 68encircling a release rod 69 the latter being pivoted to the pawl andhaving its upper end extending through the tread portion of the footlever. It will be seen that theoperator can raise the foot rest orplatform by pressing on the lever 65, the pawl sliding over the ratchetteeth and the arms 63 lifting the said platform in its guides and whenhe desires to lower it, it is only necessary to press on the end of rod69 with his toe, releasing the pawl, when he can govern the descent withhis foot as will be understood.

The arms 63 and 65 constitute in eflect but a single lever pivoted uponthe cross rod and while I prefer the arrangement shown, thisconstruction could be modified materially and produce the same result.

Pivoted to the rear of the seat frame at 69 is a casting or frame 70 onwhich the chair backissupported said frame being maintained in verticalposition by a rod 71 pivoted to it and extending through 'a pivotedclamping bolt or stud 72 journaled in a lug 73 on the back of the seatframe and fastened in any position to which it may be adjusted by ahandle 73, this construction being such that the back can readily belowered to almost a horizontal position, as in dotted lines Fig. 1, orotherwise adjusted on the pivot 'as desired.

To the front of the frame 70 are secured plates 74:, 75, having theundercut edges and forming ways in which the slide 76 carrying the backsupport operates, the rear of the slide being formed with acorresponding dovetail projection. The plate can be adj usted by meansof handle 77 so that the slide can be moved and then secured rigidly inposition. 79 indicates the padded chair back pivoted at 80 to the upperportion of the slide 76 and near its lowerportion is pivoted a pawl 81adapted to engage with the teeth of arack 82 on the slide to adjust theinclination of the back, as shown in dotted lines.

Sliding in a socket in the upper part of the slide 76 and adapted to besecured in position by a clamping screw 83 is a bent rod 84 on which thehead rest is supported, said head rest consisting of the usual pad 85 tothe rear side of which is connected a stem v86 having a ball 87 on itsend adapted to be received in and secured by the clamp 88. lhis clampconsists of two co-operat-ing sections connected by a hand screw 89,their upper portions when together constituting a spherical socket .forreceiving the ball 87 on the head rest stem, while their lower ends areprovided with the semi-cylindrical grooves fitting the sides of thehorizontal portion of the rod 84, the parts being so arranged thatbyasiug'le movement of the hand screw, the head rest can be loosened andadjusted, not only by moving the ball around in its socket but the wholeclamp. can be moved along on the rod 84 or around it, as may be desired.The advantages of this construction of head rest will be at onceapparent, as with a single clamping screw all the necessary motions ofthe pad or head rest proper are controlled. The construction of the backand the parts supported upon the seat frame also enables me to obtainall the adjustments necessary to put the patient in the most comfortableand convenient position to be operated upon.

The whole chair may be rotated around on the part 1,2, of the base withthe securing screw 8 as a center, the flange 7 offering but littlefrictional resistance on the plate 2 and in order to secure it in anyposition desiredI provide a bolt 90 in the lower portion of the part 3of the base, pressed downward into one of a series of holes 91 formedin'the top of plate 1, by a spring 92 and adapted to be, lifted andheldout of engagement, when desired, by an arm 93 engaging the inclinedorcam surface formed on. the base when turned to one side as in Fig. 5, indotted lines.

I claim as my invention. 1. In a chair, the combination with the seatstandard, of the. rotatable base in which the standard is movable, thewinding drum, the cable connecting the standard and drum, the shaftcarrying the drum, the ratchet wheel on the shaft, the pawl engagingwith it, the clutch wheel, the clutch and means for actuating thelatter, all said parts being located within the base, substantially asdescribed.

2. In a chair, the combination with the seat standard of the base inwhich itoperates, the winding drum, the cable connected to the drum andstandard, clutch mechanism for operating the drum, retaining devices forarresting backward movement the speed governor and a clutch between saiddrum and governor permitting the independent rotation of the drum toraise the standard, but causing its automatic engagement with thegovernor when rotated in the opposite direction, substantially asdescribed.

3. In a chair, the combination with the base, the seat standard thecable, the shaft having the drum, the ratchet wheel and clutch devicesactuated from the exterior of the base, of the speed governor, the gearon the shaft connected with the governor, and the clutch between thegear and drum whereby the drum is rotated-in one direction,substantially as de-' scribed.

5. The combination with the base 8, the seat standard operating therein,the shaft, the drum fixed on the shaft, the liftingcable, the

gear loose on the shaft and the clutch between it and the drum, of thespeed governor and gearing between it and the first mentioned gear,ofolutch devices for rotating the drum and devices for securing it frombackward rotation, substantially as described.

6. The combination of the base, the seat standard, the shaft, the drum,the cable connected to the standard and drum, the gear,

and a clutch connecting it with the drum when i the latter moves in onedirection, the vertical shaft having the pinion in engagement with thegear,the horizontally rotating spider having the gear and the weightedbrake shoes[ and the gear on the vertical shaft engaging the one on thespider, substantially as described.

7. The combination with the base or column containing the liftingmechanism and the seat standard operating therein, the base casting 4secured to the column having the central boss, the spider mountedthereon having the weighted brake arms co-operating with the rim of thecasting constituting a speed governor, and gearing connecting the spiderwith the lifting mechanism, of the base plate and the pivot boltentering the casting at and securing it to the said plate, substantiallyasdescribed.

8. In achair, the combination with the base, seat standard, and thelifting mechanism for the latter having the movable pitman, of thelifting lever pivoted in the base, the stud on thelever embracing thepitman and detachable connections between said stud and the pitman,whereby the lever may be-disconnected and allowed to fall beside thebase, substantially as described.

9. The combination with the chairbase, the

pivoted lever, having thestud and spring projected bolt, of the pitmanhaving'the recess with which the bolt co-operates for-locking it to thepitman and means for operating said bolt, substantially as described.

10. The combination with the chair base, the pivoted lever the studmounted thereon having the spring projected bolt, the lever connected tosaid bolt and adapted to be operated from the exterior of the chairbase, of the pitman connected tothe seat lifting mechanism passingthrough the stud and having the recess with which the bolt co-operates,substantially asdescribed.

'11. The combination with the chair base, the pivoted lifting lever, thestud pivoted thereon having the aperture and the spring projected bolt,the lever mounted-on the-pivot of thelift-ing lever andthe linkconnecting a it with the bolt,-of the pitman connected to the seatlifting mechanism passing through the stud and havingthe recess withwhich the bolt co-operates, substantially as described.

12. The combination with the seat frame having the depending armsconstituting guides and the segmental rack thereon, of the platformsliding in said arms, the foot lever pivoted on said depending armshaving forwardly extending armsprojecting beneaththe platform and onwhich it is supported and 1 the spring operated pawl engaging the rack,

substantially as described.

13. The combination with the seat frame having the depending armsconstituting guides, the bolt or rod connectingthem and the segmentalrack, of the platform sliding on said arms, the sleeve encircling therod having the forwardly extending arms proj ecting beneath andsupporting the platform, the 'rearwardlyprojecting foot lever, thespring pawl thereonco-operating with the'rack, the rod connected tothepawl arranged in proximity to the tread of the lever, whereby theoperator may operate the footlever to raise the platform or release thepawl and govern its descent, substantially as described.

MAGULER BUTLER.

Witnesses:

FRED F. CHURCH, A. A. DAvIs.

